What principles guide scale-up from pilot to commercial plant?

Scale-up principles: Geometric similarity - maintain ratios (L/D, internals dimensions) where important. Kinematic similarity - same velocity ratios, flow patterns. Dynamic similarity - match dimensionless numbers (Re, Nu, Da) where governing. Heat transfer scaling - surface/volume ratio decreases; may need internal cooling. Mixing scaling - maintain power per volume or tip speed depending on application. Reaction scaling - residence time distribution, heat/mass transfer effects. Not everything scales linearly - identify critical parameters. Scale-up factors: surface area scales as L^2, volume as L^3. Pilot requirements: operate at commercial conditions where possible, include all process steps, measure everything. Risk mitigation: intermediate scale (demo plant), parallel trains, conservative design margins. Documentation of scale-up basis essential for troubleshooting.